Contact spring retainer



May 19, 1959 s. DETWILER 2,887,551

CONTACT SPRING RETAINER Filed Aug. 3, 1956 FIG.

INVENTOR Harry S. Detwiler ATTORNEY United States Patent CONTACT SPRING RETAINER Harry S. Detwiler, Lancaster, Pa., assignor to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Application August 3, 1956, Serial No. 601,900

7 Claims. (Cl. 200-166) This invention relates to an improvement on the spring contacts used in electric watches, and more particularly to a means for preventing the spring contacts from getting out of alignment.

It is the object of the present invention to provide a retainer or restricting ring which may be attached to one of a pair of spring contacts used in an electric watch, the other contact being retained within the confines of the ring to prevent one of the contacts from springing over the other.

A further object of the present invention is to provide means for retaining a pair of contacting springs in contact making relation, one of said springs serving as an electrical conductor in an electrically operated watch.

'It is a still further object of the present invention to provide a metallic closure or ring which may be affixed to one of a pair of spring arms and used to house the other of the spring arms to prevent said arms from becoming out of alignment.

A still further object of the present invention is to provide a retaining member attached to one of a pair of spring arms which are in stressed position and opposed to each other, said retaining member housing the other of said spring arms to prevent their losing contact with each other.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a plan view of the spring arms and the contact member carried on the oscillating balance staff of awatch.

Figure 2 is a detail of the spring arms showing the retaining member and spring arms greatly enlarged.

Figure 3 is a detail of a modification.

Referring to the drawings, Figure 1 is a greatly enlarged view of the contact system of an electric watch having a balance staff 11 which ordinarily supports a balance wheel and hairspring assembly, not shown, and carries a roller 12 and contact making arm 13..

The contact arm is upturned at its end, as shown at 15, and makes contact with a contact button 16 carried on the end of the spring wire 17. This spring wire is mounted in a collet 20 which is carried on a contact post 21 which in turn is connected to a battery, not shown. The collet 20 is rotatable about the post 21 to angularly position the spring wire 17. The spring wire 17 is furthermore slidable in the slot 22 of the collet which provides for longitudinal adjustment of the spring wire, and a consequent adjustment of the contact button 16 relative to the contact arm 15.

A second spring arm 25 is mounted in a slot 26 in collet 27 carried on post 28, which spring wire is likewise adjustable longitudinally and angularly on the post 28 in a manner similar to that of the spring wire 17. The extreme end 29 of the wire 25 contacts the jewel pin 31 carried on the roller 12 during the oscillating movement of the balance staff 11.

A retaining member 35 in the form of a rectangular 2,887,551 Patented May 19, 1959 band having one end 36 overlapping is supported by the spring wire 25 and confines spring wire 17 within its limits. This retaining member prevents the contact spring wire 17 from changing its relative position to the wire 25 except by an exceedingly small amount and insures that the wire 17 will maintain a position below the wire 25, referring to Figure 1. It is necessary for the operation of the watch that the wire 17 be below or in back of (referring to Figure 1) the wire 25 so that the inherent resiliency of the wires is effective towards maintaining a stressed position in the contacts.

The wires 17 and 25 due to the angular position and to their inherent resiliency are held in a stresesd position, exerting a force against each other through the retainer member. This stressed condition is necessary so that upon engagement of the contact button 16 with the contact face 15 there is no undue vibration or chatter in the contact, the force against the surface of the contact will be constant throughout the entire contact period and will not change due to change of position of the contact face 15 through rotation of the roller 12.

In the operation of the contacting mechanism and the part which the retaining member plays, a counterclockwise movement of the balance staff 11 brings the jewel pin 31 into contact with the extreme end 29 of the spring 25, as shown in the lower dotted position of Figure 1. At this time the two wires 17 and 25 are urged toward each other, the wire 17 being restrained by the retaining member 35 from passing over the wire 25. Continued movement of the roller brings the wires to the solid line position shown in Figure 1, in which the contact button first makes contact with the contacting face 15 of the arm 13. The upper dotted line position shows the wires in the last stage of the contact making interval in which the end 29 is about to lose contact with the jewel pin 31 and the button 16 is still in contact with the face 15, the wires 25 and 17 being separated by the extent of the retaining member, being forced away from each other by the influence of the jewel pin 31 and the contact face 15 during the rotation of the balance staff in a counterclockwise direction. At the moment at which the end 29 passes the end of the jewel pin, the wire 25 is released and springs backward bringing the side of the retaining member against the wire 17 and sharply breaking the contact between the button 16 and the face 15. The retaining member permits sufficient separation of the wires to avoid any interference during the contact making interval, but is sufficiently small to retain the wires in practical contact with each other. On the return motion of the balance staff 11, the end 29 is engaged by the jewel pin 31 and through the retaining member 35 swings the wire 17 clear of any contact with the contact face 15.

Referring particularly to Figure 3, a modification of the retainer ring is shown in which instead of the substantially ribbon shaped strips used for the spring wires, round wires 40 and 41 are used. The wire 41 carries a contact making member similar to the wire 17, while the wire 40 serves the same purpose as the wire 25. Instead of a separate retaining member, such as 35, the wire 40 is bent into a loop 43 through which the contact carrying wire 41 is threaded. This serves the same purpose as the retaining member 35 and would be especially appropriate should round wires be found desirable. The ribbon shaped wires, such as 17 and 25, are used because they permit greater flexibility in one direction and retain a certain amount of rigidity in the other direction.

What is claimed is:

1. In an electric watch a stressed elongated spring contact member, a stressed elongated spring member in engagement therewith and opposing the spring force of said contact member, and retaining means permitting com plete separation of said members-only in a direction substantially in the plane of said members.

2. In an electric watch, a stressed elongated spring contact member, a stressed elongated springme'mber in engagement therewith and opposing the spring forceof said contact member, and retaining means carried by one of said members permitting complete separation of said members only in a direction substantially in the plane of said members.

3. Apparatus as defined in claim 2 in which said retaining means is detachably secured to said one member.

4. Apparatus as defined in claim 2 in which said re taining means is integral with said one member.

5. In an electric watch, a stressed elongated spring contact member, a stressed elongated spring member in engagement therewith along the length of said members and opposing the spring force of said contact member, and retaining means comprising a loop carried by one of said members and completely encircling the other of said members.

6. Apparatus as defined in claim 5 in which said encircling loop is spaced from said other member permitting limited separation of said members.

7. Apparatus as defined in claim 6 in which said loop is positioned at a point of contact between said members.

References Cited in the file of this patent UNITED STATES PATENTS 1,748,219 Hanel Feb. 25, 1930 1,830,138 Smith Nov. 3, 1931 2,522,895 Raymond Sept. 19, 1950 

